BAD NIGHT: Johan Santana hangs his head in the dugout after being removed from the game in the second inning of the Mets’ 9-3 loss to the Braves last night at Citi Field. Photo: Paul J. Bereswill

How about benching Johan Santana and turning to Tim Tebow?

Every option should be explored by the Mets after last night’s Citi Field debacle made it clear all remains wrong with their former ace.

Santana’s first major league start in three weeks turned into an avalanche, with the lefty smothered by debris before he could escape the second inning in the Mets’ 9-3 loss to the Braves.

The brutality included eight hits and eight earned runs allowed by Santana over 1 1/3 innings, raising further questions about the fitness of his surgically repaired left shoulder.

Considering the Mets still owe Santana $31 million beyond this season, any concerns are justified.

Over his last four starts, Santana is 0-4 with a 17.36 ERA, having allowed a preposterous 36 hits in 14 innings. The Mets had hoped the 21 days he spent on the disabled list before last night would serve the dual purpose of allowing a sprained right ankle to heal while resting his shoulder, but there was no sign of progress.

“I’m just going through a tough stretch — I’m struggling — but I’ve just got to bounce back,” Santana said. “I haven’t pitched for the last three weeks, but it takes a little bit of time. The situation we’re in, we can’t afford to wait or make mistakes, especially in my case, because I want to help as much as I can.”

The carnage was complete after Freddie Freeman greeted reliever Jeremy Hefner with a three-run homer that cleared the apple behind the center-field fence. Santana (6-8) allowed a walk and five singles in the inning before manager Terry Collins yanked him.

“I’d say it was rust,” Collins said. “That’s probably the best fastball I’ve seen him have since early in the season, it’s just fastballs in the middle of the plate. As I told him when I took him out — no disrespect to the Braves, because they’ve got a very good club — when they hit it, they hit it where nobody was standing. He didn’t have the ball hit at anybody.”

The Mets (54-60) lost for the fifth time in six games and fell a season’s worst six games below .500. They are 8-20 since the All-Star break and 1-11 at home in the second half.

Santana’s start last night matched the shortest of his career. On April 17 at Turner Field, he also lasted just 1 1/3 innings against the Braves, allowing six runs — two were unearned — on four hits and a walk.

“You look at the games where he has pitched well, lots of swings and misses, lots of called strikes, and right now they’re not swinging and missing it,” Collins said. “There’s got to be a reason, and there are a couple of things we’re going to talk about.”

Neither Santana nor Collins ruled out the possibility the lefty could be shut down for the season.

“The good thing is that my shoulder is fine from surgery, and that’s something that we talk about,” Santana said. “I’m hoping to finish the season pitching, but I don’t know later on what’s going to happen. I’ve just got to prepare for my next game and see what happens from there.”

Should the Mets choose to shut down Santana, they would likely stick with Hefner in that spot for the remainder of the season, or at least until September, when Jeurys Familia and Jenrry Mejia could become options.

“[Santana’s] health is the most important thing, getting through the season I think is pretty important,” Collins said. “Do we go to a sixth guy so he and Chris [Young] have some extra days? That’s all going to be talked about.”